It is well known that pipe clogging solids are produced if hot hydrocarbons are cooled as they flow out of hydrocarbon reservoirs. This is a particular problem in the production of hydrocarbons from offshore wells because the hydrocarbons are immediately subjected to the seawater temperatures if they pass through uninsulated pipes located near the ocean bottom. Specifically, cooled hydrocarbons form hydrate solids which can significantly reduce the internal flow diameters of production piping. Accordingly, there is a need in the art to provide a low cost, effective thermal insulation material for the external coating of pipes used in the subsea production of hydrocarbons. Such thermal insulation material should have sufficient strength and compressibility to withstand the rough handling of pipe normally associated with the production of hydrocarbons.
Some users of pipe to produce hydrocarbons from subsea wells have tried using thermoplastics such as polypropylene or polyethylene for thermal insulation. While effective for retaining heat, it has been found that such thermoplastics are difficult to apply to the external surface of pipes.
One of the best thermal insulating materials developed in recent years is the microballoon; however, heretofore there have been no method or systems in which microballoons can be effectively applied as thermal insulation to the exterior surface of pipes for use in hostile environments such as in the subsea production of hydrocarbons.
It has been proposed to use oil based epoxies to form a matrix to support the microballoons; however, such oil based epoxies are difficult to apply to the exterior of pipes and are notorious for making application equipment hard to clean.
The need, therefore, remains in the art for a system which will allow for the use of microballoons as a thermal insulating material for the exterior surface of pipes.